Round counter for firearm

Abstract

A round counter for a firearm is provided that includes a display that provides the user with information regarding the number of rounds remaining in the magazine of the firearm. The magazine includes a round follower and a wiper extending from the follower. The wiper contacts a variable resistance sensor, such as a linear potentiometer, that is attached to a sidewall of the magazine. As the round follower and wiper move up and down within the magazine, the wiper contacts the sensor at different positions. The position of the wiper relative to the sensor corresponds to a specific linear distance indicative of the number of rounds remaining in the magazine. Information regarding this position, and consequently the number of remaining rounds is transmitted to the display.

What is claims is: 
     
         1 . A round counter for a firearm comprising:
 a magazine adapted to store a plurality of ammunition rounds for use in the firearm;   a round follower positioned within the magazine below the plurality of ammunition rounds;   a biasing member that applies an upward force on the round follower;   a variable resistance sensor;   a wiper that is connected with the round follower and that contacts the sensor; and   a display that displays information relative to the number or ammunition rounds remaining in the magazine.   
     
     
         2 . The round counter of  claim 1  wherein the biasing member is a spring. 
     
     
         3 . The round counter of  claim 1  wherein the sensor is a contact sensitive variable resistance sensor. 
     
     
         4 . The round counter of  claim 1  wherein the sensor is a linear potentiometer. 
     
     
         5 . The round counter of  claim 1  wherein the sensor is a membrane potentiometer. 
     
     
         6 . The round counter of  claim 5  wherein the membrane potentiometer comprises a top circuit, a circuit spacer and a bottom circuit. 
     
     
         7 . The round counter of  claim 1  wherein the sensor is attached to an inside surface of a sidewall of the magazine. 
     
     
         8 . The round counter of  claim 1  wherein the wiper extends from the round follower and contacts the sensor with sufficient pressure to activate the sensor. 
     
     
         9 . The round counter of  claim 8  wherein the wiper extends from the round follower at an angle that is substantially perpendicular to a direction of movement of the round follower. 
     
     
         10 . The round counter of  claim 8  further comprising a spring that biases the wiper to provide pressure on the sensor. 
     
     
         11 . The round counter of  claim 1  further comprising an identification tag attached to the magazine. 
     
     
         12 . The round counter of  claim 11  wherein the identification tag is encoded with unique identification information. 
     
     
         13 . The round counter of  claim 1  further comprising a transmitter that transmits information to the display relating to the number of rounds remaining in the magazine. 
     
     
         14 . A round counter for a firearm comprising:
 a magazine adapted to store a plurality of ammunition rounds for use in the firearm, the magazine comprising a magazine body having a sidewall;   a round follower positioned within the magazine below the plurality of ammunition rounds, the round follower moving within the magazine body as ammunition rounds are added to or removed from the magazine;   a linear potentiometer attached to the magazine body sidewall;   a wiper that is connected with the round follower and that contacts the linear potentiometer;   one or more electronic components that receive information from the linear potentiometer relating to the position of the wiper and that transmit information relating to the number of ammunition rounds remaining in the magazine; and   a display that received the information from the electronic component and displays information relative to the number or ammunition rounds remaining in the magazine in a user readable format.   
     
     
         15 . The round counter of  claim 14  wherein the position of the wiper relative to the linear potentiometer corresponds to a specific linear distance indicative of the number of rounds remaining in the magazine. 
     
     
         16 . The round counter of  claim 14  wherein the display is a digital numeric display. 
     
     
         17 . The round counter of  claim 14  wherein the electronic components comprise a power source. 
     
     
         18 . The round counter of  claim 14  wherein the electronic components comprise:
 an analog to digital converter that comprises an input connection that receives signals provided on an output connection of the sensor and an output connection; 
 a digital signal processor that comprises an input connection that receives signals provided on an output connection of the analog to digital converter and an output connection; and 
 a transmitter that comprises an input connection that receives signals provided on an output connection of the digital signal processor and transmits signals to a receiver connected with the display. 
 
     
     
         19 . The round counter of  claim 18  wherein the transmitter is a wireless transmitter. 
     
     
         20 . The round counter of  claim 14  further comprising a switch that is activated when the magazine is inserted into the firearm.